At 10:34 PM -0600 3/7/02, Lance Spitzner wrote:
>Most honeypots work on the same concept, a system that has no
>production activity. You deploy a box that has no production
>value, any packets going to that box indicate a probe, scan, or
>attack. This helps reduce both false positives and false
>negatives. Exampls of such honeypots include BackOfficer Friendly,
>DTK, ManTrap, Specter, and Honeynets.
>>However, I was just thinking, why bother deploying the box?
>Why not create a list of Snort rules that generate an alert
>whenever a TCP/SYN packet or UDP packet is sent to an IP
>address that has no system? This could incidate a probe,
>scan or attack, the same principles of a honeypot, but
>without deploying an actual system.
>>Of course this does not give you the Data Capture capabilites
>of a honeypot, as there is no system for the attacker to
>interact with. However, this could be used to help detect
>scanning or probing activity.
>>Thoughts?
Hello Lance,
This is basically what Spade does. In addition it catches to unused
or rarely used ports on valid IPs. Basically how it operates is that
it keeps a summary record of packets (by default the dest IP and dest
port combo) it has seen. From that it can assign an anomaly score
based on the unusualness of a new packet. For more details, you
might be interested in reading our "Practical Automated Detection of
Stealthy Portscans" paper on Silicon Defense's web site:
http://www.silicondefense.com/research/pubs.htm
Stuart wrote a pretty good section (IMHO) in this about stealthy
portscans, scan footprints, etc. You can also read how we got Spade
to be as fast as it is. (Running Snort Spade-only on our local
office's server processed a file of 1.25 million SYN packets in a
little over a minute. YMMV of course.)
Best regards,
Jim
--
|* Jim Hoagland, Associate Researcher, Silicon Defense *|
|* --- Silicon Defense: IDS Solutions --- *|
|* hoagland at ...47..., http://www.silicondefense.com/ *|
|* Voice: (530) 756-7317 Fax: (530) 756-7297 *|